Waiter



April 28, 1953 M, WATTER 2,636,968

SEALED SEA ATTACHMENT OF CORRUGATED SHEET METAL Filed July 23, 1948 :FICLZ 1b JNVENTOA Michael Waite/t.

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Afrox/vn M. wATTER' 2,636,968

SEALED SEAM ATTACHMENT 0F CORRUGATED SHEET METAL 2 SHEETS- SHEET 2 i A Y man INVENTOIL Michael Wai fer ATTORNEY Patented pr. 28, 1953 SEALED SEAM ATTACHMENT OF CORRU- GATIED SHEET METAL Michael Watter, Philadelphia, Pa., assigner to The Budd Company, Philadelphia, Pa., a corporation of Pennsylvania Application `luly 23, 1948, Serial No. 40,238

(Cl. 21S-16) l1 Claims.

The invention relates principally to the structure and to the making of a sealed seam (i. e., iiuidand dust-proof) attachment of a corrugated sheet metal `member to another metal member along a margin traversing the corrugations.

More specifically, the invention relates to sealed seam connections between an outer corrugated skin or sheathing and adjoining members of vehicle bodies, especially railway cars, highway trailers and the like.

en object of the invention is to obtain a connection or attachment of the indicated type which is 'truly fluidand dust-tight, which is dependable durable, which can be made conveniently on a production basis vand which, above all, avoids the necessity of using solder, with its many drawbacks.

The objects and advantages of the invention are achieved through the attachment of the locally nattened corrugations to the underlying member by a continuous electric resistance seam weld which not only unites the directly contacting surfaces of the corrugated sheet and the underlying member but also unites the reversely bent, flattened wall portions of the corrugations with each other by a substantially homogeneous, continuous zone of fused metal.

The manner in which the above and further features, objects and advantages of the invention are achieved is fully disclosed in the attached drawing and the following detailed description.

ln the drawing:

Figure 1 is a small-scale diagrammatic side elevation of the end region of a railway-car having a corrugated metal roof sheathing;

Figure 2 is an enlarged fragmentary view of the region surrounded by the dct-and-dash line 2-2 of Figure 1;

Figure 3 is a fragmentary section, on a still larger scale, along line 3-3 of Figure 2;

Figure Ll is a fragmentary perspective view of one corrugation and the underlying structure prior to the establishment of the sealed seam;

Figure 5 is a fragmentary section along line 5 5 o Figure 4 and a diagrammatic side view of a spot welding electrode;

Figure 6 is a diagrammatic, partly sectional, view along line isfof Figure 5 illustrating the sequence of certain initial welding Operations;

Figure 7 is a fragmentary section taken along line l-'a' of Figure 2;

Figure 8 is a perspective diagrammatic view corresponding to Figure 4 showing the completed joint between the corrugated sheet and the underlying member;

Figure 9 is a section along line 9 9 of Figure 7 through the completed sealed seam along its longitudinal extent; and

Figure 10 is a fragmentary perspective view corresponding to Figure 4 but illustrating a modiiication of the flattening of the corrugations.

The railway car body illustrated in the drawing has a roof skin or sheathing I5 of longitudinally corrugated sheet metal secured at its ends to a shear panel I6 of dat stock and an end wall panel Il reinforced peripherally by angle-section rails I8 and I9 which support member IG. The corrugations or nodes of sheet I5 have bottom walls 20, side walls 2l and top walls 22. The bottom walls 26 are structurally connected by spaced spot welds 23 to the underlying structural member I6.

For obtaining a fluid-tight closure of the ends of the corrugations in the known construction described so far, it has been a practice to flatten the ends of the corrugations, as shown in Figure ll, and then close the remaining openings or passages by applying solder to the members I5 and IS in a narrow region on both sides of the edge of the corrugated sheet. As indicated above, this soldering procedure has numerous serious drawbacks, inasmuch as it is expensive, on account of the high cost of the solder and the time required for its application, as it requires skilled, meticulous workmanship and as it impairs the appearance, especially when the structure consists of shiny metal, such as stainless steel.

In carrying out the invention, care is taken that a marginal strip 24 of a certain width, Figure 5, is iiattened so that in this region wall portions of the corrugations are folded back upon each other in three layers, 25, 26 and 2l, whereas the intervening portions of the bottom and top walls 26 and 22, Figure 6, remain single-layer. The extreme edge portion of the corrugated sheet is secured to the underlying member I6 by a continuous electric resistance weld 28 which fairs the edge of the corrugated sheet into the outer surface of member IE5 and integrally connects the r three layers 2S, 25, 2l without leaving any passages transversely to the edge of the corrugated sheet. Thus, a sealed seam is formed, as shown in Figures 3, '7 and 8.

An effective method of obtaining the weld connection 28 comprises the following steps:

After the corrugated sheet I5 is iiattened at 24 and structurally connected to the member I6 by welds 23, single spaced welds are irst made along the edge of the corrugated sheet at about the centers of the flattened tops 22 of the nodes, as indicated by the position ofthe electrode 29 shown in full line, and in each triple-layer region 25, 26, 21, as indicated by the positions of the electrode shown in dotted and dot-and-dash lines 3S, 3l, respectively, in Figure 6. These three locations on each corrugation Were found to be somewhat critical, and it was discovered that the seam couldfbe mademorexeasily, ecoenomicallyffand'safely lbystarting the -Welding at these three locations rather than making the continuous close-space spot or seam Welding at``v once. The single Weld operationsorge the three.- layers 25, 26, 21 together and force theendsf'of the top Walls into contact with the member i6.

Upon completion of the singlefvvelds= at thea margin, the corrugated sheet'lS is secureduidLf tightly to the underlying structure l5 by closespace spot Welding, such as tangent..vvelding, er.: by seam welding. This produces the continuous seam 2e and may also fairv the edge ofsrieetf' iE' into member I6.

Inmakingttie eweldsgthe -electroidesfare :prefere ably vplaie-ediena-.thefevery edgeofi corrugated lsheet i5, so that about two-thirdsioffthenmntact:sur-A faceiofsthe:electrndessarezover; the sheet, Where,-

ass; the oneetliird; proj ectsi. outwardly:V

`tifiereneycn assillustratedziin:Figure: 5. This vrlo:-4 catieniofi theielectrosiesy.coupledewitli :a ,relatively highelctrode pressure; facilitates thelforgingrtoe.

tapering; offtrie entireatedgezof"'sheetzi5; resulting. intthementinuous Weldiand the merger-or fair-v.

ingf'ofthe;simiaceaoffsheet:1i 5 intofthesurfacezcf l memh'erzzt t Ecrrreasonszofsimplicityfand economy. 0fpro..

cedure, theflast'welding step: is-carried out .Withi by molten: metal.` scnzeeredk outf beyondl the edge cifftliersrieet fii If" necessary-or desirable, the

Weld region is subsequently"smoothed'and theAV iceseebarblssremovedibyannropriate means; such isthr-:nasfshowniiiiigure 8f butin-many cases; the-"edgewill i beleven-more' uniforrrrI and; havega less irregulararna'reinal line,- d'ependingonv4 thel properJv adjustrnenty off' all factors` involved andunon the skill exercised'byY the'workman:

The` finished3 composite structure- E55, it;V to*- getl'ier withjotlierelements'offtheroof structure, ist placed ontherailsi I storend' Wall lland is secured to rail i by' Welds' 32".. A: caulking compot-oldie placed' at" b'etweentlie' rails'. l il, it to...

seaigtheconnection between end "wall andlroof.

While the stresses between' theroot'skin. i5,V

which, in the iliustrated embodiment', constitutes:

a structural element .oigthe body, ,and'lthe member imnortantjthatjthe seallliave.sircientistrengthto avoidtearingnutnr. cra-cking .Whensubi ectedf tea, certain unavoidablefamount.ofstress.., Thisisthe. caseavitntheseal.formed .by weld 2&1,V

Ei'gurall) illustrates a.novel. way` of. i'iattening.; tlielA ends of. thacorrugations, preparatory. to the.,

establishment of the sealed seam. The sheet 36 has corrugations formed by bottom walls 35, side Walls 355 and 3l and top Walls 38. The ends of the corrugations are flattened tovvard one side by straightening out the adjoining bottom walls 35, side walls 3e and top walls 38 While folding the otherside Walls 37Vbetweentlfie-itopl and bottom walls: The exact location ofA the-creases is, of course, dictated by the shape and dimensions of the-corrugations. Also for this formation it is advisab-letofmake'single welds at least in the threelayer-:regions and possibly in regions adjacent thereto, before completing the continuous seam.

The inventionhas `particular advantages over sea-ls obtained-bysuch means as gas or arc welding inv itsV application to cold-rolled austenitic highetensile, stainless steel. The weld timing and' heat. input of electric resistance welding,

usedtinconnection with the invention, can easily be regulated and kept at a minimum in accordance with knot-vnf rules-i for;` avoiding.; deleterious changesrfotthe' physical. :andchemical apropertiesf. oitliis-A type ori material. Nerf iss there undue; weake'iingf.` otr* the f coldeworked; strength` by the: annealingA incidentall to;l the? welding? operation;- because the extent of annealed zone is kept small.

Similar-considerations:apply alsoftocther metals having desirable-qualities whichzmayzbe aected: byy prolonged orfintensive heating; connected, .fort insta-nce, witharc `or gas-Welding:

The invention is not restricted'itozthe illustrated.- andi describedk embodiment; norrto1 all the'. details thereof," ass` indicated by: tli'ezfollowing enumerare tionfcfsome examplesoiA available variants;v @be vicusly; electrode: diameter,` electrode pressure,l Weldf spacing,t` etc.; havey to belacljusted to the natures and the gauges of theu materials to'. be; welded together. Furthermore-,1. adjustments-1 may* be'. made"- se'v asffto lcarryI outathe; invention with avail'able'iWeldi-ng equipment.' 'Ifile-'resultI achievedir'r -thethree-'l'ayer regions by `the initial" Welds may'y also `fbeachieved 7by other means `forgingt'n'elayersftogetlier: preparatory to the vniaking' of i tl'iev' continuous Weldl There is a" great latitudein' regard'l to thefspacingv ofisuccessive,A welds: While any overlapV of? about 25% isffsuge-A geste'd above;` awviderlspacing;irl-Which thewveldir nuggets i ust touch .each otheror are veven 'slightly spaced Without,v heavingV aV` passage forv iiuidY betvveen'tliem; is satisfactory; Not only the ends 'ofi a sheet;butialsuimarginsat cut-outs, openings and the like'may'besealed ofi in the same'manner. The invention may also beused-:or-securirigva rcorrugated sheet intermediate vits'endsttoa. member, such aste. amargin of. a partition Wall; by` iiatteningthe:corrugaticns jin Vthe attachment zone.. andthen. closing.r all' ipassages in thelongi-Y tudinal direction of the corrugationsbyg prac` tically continuous ...resistance .weld' which obliterates in its-zone-the..multielayer. structure and.. makes.- al homogeneous-u-nit of all layers or", the corrugated sheetand:thefunderlyingstrncture to which; it; isasecured. The, yterm eerruga-tionl is.:` to fb'ea understood cina-broad :'sensef, anditheinvention is" applicablefto the; atta-'chmentioffhatesec-n tions, sheets having Widelyrspacedinodes orchanx nels; on having' forf other reasons, multillayer regions;v which hitherto' were deemedV to prevent theI formation of. a4` continuous' tight seam" by'V means ofresistance welding.

Protectionissought in.the...light of theseex.- planationsior, basicieatures .oE the. invention', Ain addition. to, protection for. more. specic.. illus-V trated and described features What is claimed is:

1. In a structure comprising a metal sheet provided with corrugations and overlappingly contacting another metal member, said corrugations being flattened in a localized elongated region extending transversely to the corrugations by having portions of the sheet folded in three layers reversely upon each other, and an elongated electric resistance weld in said region uninterruptedly connecting said sheet and member by their own substance at their interface, extending through said layers and filling all passages between sheet and member and between said layers, whereby a sealed seam is formed.

2. In a structure comprising a metal sheet provided with corrugations and overlappingly contacting another metal member, said corrugations being locally flattened along a margin of the sheet extending transversely to the corrugations, the flattening comprising portions of the sheet folded in three layers reversely upon each other, and a practically continuous electric resistance weld along said margin uninterruptedly connecting said sheet and member at their interface by fused parts of their own substance and extending through said layers in closing all passages between sheet and member and between said layers.

3. In a structure comprising a metal sheet provided with corrugations and overlappingly contacting another metal member, said corrugations Y being flattened in an elongated region extending along one margin of the sheet transversely to the corrugations by having portions of the sheet folded in three layers reversely upon each other, and an elongated electric resistance weld uninterruptedly connecting the margin of said sheet and said member at their interface, extending through said layers and filling, by fused parts of said metal members all passages between said margin of the sheet and said member and between said layers, the surface of the sheet at the margin being tapered and faired into the surface of said member.

4. In a fabricated structure, a sheet metal member provided with at least one channelsection formation and overlappingly contacting a surface of another` metal member, said channel-section formation having a restricted region flattened by reverse three-layer folds of portions of the sheet member, said three-layer folds being reduced in aggregate thickness to the thickness of the adjoining portions of the sheet member along an elongated zone extending transversely to the channel-section, and a continuous electric resistance weld connecting in said zone the sheet member to said other member at their interface and extending through said three-layer folds thereby forming a sealed seam between the two members free of extraneously supplied sealing material.

5. Sealed seam between a margin of a metal sheet and the surface of an underlying metal member at a distance from the margins of the latter, comprising a continuous electric resistance weld connecting said sheet and member at their interface along the extreme limit of said margin and fairing the outer surface of the sheet into the adjoining surface of said member.

6. In a fabricated article, a sheet metal structure overlappingly contacting a surface of another metal member and having a multi-layer formation adjoined by a single-layer formation, said multi-layer formation being reduced in aggregate thickness to the thickness of the adjoining singlelayer formation in an elongated zone traversing both formations, and a continuous electric resistance weld providing a fused inclusion formed by the parent metal of said metal structure and member, said inclusion connecting in said zone the sheet metal structure to said member at their interface and extending through said multi-layer formation thereby forming a sealed seam between said structure and said member.

7. Method of making a fluid-tight connection between an edge of a corrugated metal sheet and a surface lof another member, comprising the known step of flattening the corrugations along the margin to be sealed so that the side walls and adjoining wall portions of the corrugations are reversely bent upon each other in three overlapping layers, the step of securing by single spot welds th-e walls forming the uppermost layers along said edge to the underlying member at points adjacent the reversely bent portions and of securing by single spot welds the three layers to each other and to said member, and the step of forming a continuous electric resistance weld seam between said edge of the corrugated sheet and said member.

3. In a method of making a fluid-tight connection between the edge of a corrugated metal sheet and an underlying hat surface metal member by electric resistance welding, comprising the step of flattening the ends of the corrugations along the edge to be secured and of making the welds by an electrode placed on the edge of the corrugated sheet so that part of the contact surface of the electrode projects beyond such edge.

9. In a method according to claim 8, in which the part of the electrode contact surface located on the corrugated sheet is greater than the part which extends beyond the edge of the sheet.

10. In a method according to claim 8, in which about one-third of the electrode Contact surface extends beyond the edge of the corrugated sheet.

l1. Method of making a uid-tight connection between the edge of a corrugated sheet and a surface of another member, comprising the step of flattening the corrugations along an elongated zone so that the side walls and adjoining wall portions of the corrugations are reversely bent upon each other in three overlapping layers, and the step of forming a continuous electric resistance weld seam in said Zone between said corrugated sheet and said member in using an electrode pressure forging the three layers together and reducing their aggregate thickness to about the gauge of the sheet.

MICHAEL WATTER.

References Cited in the file 0f this patent UNITED STATES PATENTS Number Name Date Re. 16,276 Cary Feb. 23, 1926 1,541,513 Knoop June 9, 1925 1,617,114 Hohhn Feb. 8, 1927 2,016,380 Lutz Oct. 8, 1935 2,073,684 Coakley Mar. 16, 1937 2,175,071 Walker Oct. 3, 1939 2,190,621 Baer Feb. 13, 1940 2,209,909 Whitesell, Jr. July 30, 1940 2,257,084 Dean Sept. 23, 1941 2,324,435 Smith July 13, 1943 

